1 /*
2 * Copyright (C) 1984-2002 Mark Nudelman
3 *
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
6 *
7 * For more information about less, or for information on how to
8 * contact the author, see the README file.
9 */
10
11
12 #include "less.h"
13
14 extern IFILE curr_ifile;
15 extern int sc_height;
16 extern int jump_sline;
17
18 /*
19 * A mark is an ifile (input file) plus a position within the file.
20 */
21 struct mark {
22 IFILE m_ifile;
23 struct scrpos m_scrpos;
24 };
25
26 /*
27 * The table of marks.
28 * Each mark is identified by a lowercase or uppercase letter.
29 * The final one is lmark, for the "last mark"; addressed by the apostrophe.
30 */
31 #define NMARKS ((2*26)+1) /* a-z, A-Z, lastmark */
32 #define LASTMARK (NMARKS-1)
33 static struct mark marks[NMARKS];
34
35 /*
36 * Initialize the mark table to show no marks are set.
37 */
38 public void
init_mark()39 init_mark()
40 {
41 int i;
42
43 for (i = 0; i < NMARKS; i++)
44 marks[i].m_scrpos.pos = NULL_POSITION;
45 }
46
47 /*
48 * See if a mark letter is valid (between a and z).
49 */
50 static struct mark *
getumark(c)51 getumark(c)
52 int c;
53 {
54 if (c >= 'a' && c <= 'z')
55 return (&marks[c-'a']);
56
57 if (c >= 'A' && c <= 'Z')
58 return (&marks[c-'A'+26]);
59
60 error("Invalid mark letter", NULL_PARG);
61 return (NULL);
62 }
63
64 /*
65 * Get the mark structure identified by a character.
66 * The mark struct may come either from the mark table
67 * or may be constructed on the fly for certain characters like ^, $.
68 */
69 static struct mark *
getmark(c)70 getmark(c)
71 int c;
72 {
73 register struct mark *m;
74 static struct mark sm;
75
76 switch (c)
77 {
78 case '^':
79 /*
80 * Beginning of the current file.
81 */
82 m = &sm;
83 m->m_scrpos.pos = ch_zero();
84 m->m_scrpos.ln = 0;
85 m->m_ifile = curr_ifile;
86 break;
87 case '$':
88 /*
89 * End of the current file.
90 */
91 if (ch_end_seek())
92 {
93 error("Cannot seek to end of file", NULL_PARG);
94 return (NULL);
95 }
96 m = &sm;
97 m->m_scrpos.pos = ch_tell();
98 m->m_scrpos.ln = sc_height-1;
99 m->m_ifile = curr_ifile;
100 break;
101 case '.':
102 /*
103 * Current position in the current file.
104 */
105 m = &sm;
106 get_scrpos(&m->m_scrpos);
107 m->m_ifile = curr_ifile;
108 break;
109 case '\'':
110 /*
111 * The "last mark".
112 */
113 m = &marks[LASTMARK];
114 break;
115 default:
116 /*
117 * Must be a user-defined mark.
118 */
119 m = getumark(c);
120 if (m == NULL)
121 break;
122 if (m->m_scrpos.pos == NULL_POSITION)
123 {
124 error("Mark not set", NULL_PARG);
125 return (NULL);
126 }
127 break;
128 }
129 return (m);
130 }
131
132 /*
133 * Is a mark letter is invalid?
134 */
135 public int
badmark(c)136 badmark(c)
137 int c;
138 {
139 return (getmark(c) == NULL);
140 }
141
142 /*
143 * Set a user-defined mark.
144 */
145 public void
setmark(c)146 setmark(c)
147 int c;
148 {
149 register struct mark *m;
150 struct scrpos scrpos;
151
152 m = getumark(c);
153 if (m == NULL)
154 return;
155 get_scrpos(&scrpos);
156 m->m_scrpos = scrpos;
157 m->m_ifile = curr_ifile;
158 }
159
160 /*
161 * Set lmark (the mark named by the apostrophe).
162 */
163 public void
lastmark()164 lastmark()
165 {
166 struct scrpos scrpos;
167
168 get_scrpos(&scrpos);
169 if (scrpos.pos == NULL_POSITION)
170 return;
171 marks[LASTMARK].m_scrpos = scrpos;
172 marks[LASTMARK].m_ifile = curr_ifile;
173 }
174
175 /*
176 * Go to a mark.
177 */
178 public void
gomark(c)179 gomark(c)
180 int c;
181 {
182 register struct mark *m;
183 struct scrpos scrpos;
184
185 m = getmark(c);
186 if (m == NULL)
187 return;
188
189 /*
190 * If we're trying to go to the lastmark and
191 * it has not been set to anything yet,
192 * set it to the beginning of the current file.
193 */
194 if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
195 {
196 m->m_ifile = curr_ifile;
197 m->m_scrpos.pos = ch_zero();
198 m->m_scrpos.ln = jump_sline;
199 }
200
201 /*
202 * If we're using lmark, we must save the screen position now,
203 * because if we call edit_ifile() below, lmark will change.
204 * (We save the screen position even if we're not using lmark.)
205 */
206 scrpos = m->m_scrpos;
207 if (m->m_ifile != curr_ifile)
208 {
209 /*
210 * Not in the current file; edit the correct file.
211 */
212 if (edit_ifile(m->m_ifile))
213 return;
214 }
215
216 jump_loc(scrpos.pos, scrpos.ln);
217 }
218
219 /*
220 * Return the position associated with a given mark letter.
221 *
222 * We don't return which screen line the position
223 * is associated with, but this doesn't matter much,
224 * because it's always the first non-blank line on the screen.
225 */
226 public POSITION
markpos(c)227 markpos(c)
228 int c;
229 {
230 register struct mark *m;
231
232 m = getmark(c);
233 if (m == NULL)
234 return (NULL_POSITION);
235
236 if (m->m_ifile != curr_ifile)
237 {
238 error("Mark not in current file", NULL_PARG);
239 return (NULL_POSITION);
240 }
241 return (m->m_scrpos.pos);
242 }
243
244 /*
245 * Clear the marks associated with a specified ifile.
246 */
247 public void
unmark(ifile)248 unmark(ifile)
249 IFILE ifile;
250 {
251 int i;
252
253 for (i = 0; i < NMARKS; i++)
254 if (marks[i].m_ifile == ifile)
255 marks[i].m_scrpos.pos = NULL_POSITION;
256 }
257